Modeling and Design of Net ZEBs as Integrated Energy Systems - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 17

options are isolated thermal storage (not directly thermally coupled to
the living space) or solarium/sunspace and collector-storage walls . A
collector-storage wall - known as a Trombe wall - consists of thermal
mass that is placed directly in front of the glazing; however, this system
has not gained much acceptance since it limits the views to the outdoor
environment. Direct gain systems are the most common
implementation of thermal storage because of their simultaneous
benefits for providing passive heating, daylight, and views to the
exterior.
3. Airtight insulated opaque envelope . Such an envelope reduces heat
transfer to/from the outdoor environment, but must be chosen to be
appropriate for the local climate. In most climates, this energy efficiency
aspect is an essential part of the passive design. A solar technology that
may be employed in conjunction with opaque envelopes is transparent
insulation combined with thermal mass to store solar gains in a wall to
turn it into an energy positive thermal element. In addition to optimized
thermal response, the envelope should control air and moisture transfer
between the indoor and outdoor environments.
4. Daylighting technologies and advanced solar control systems . These
technologies provide passive daylight transmission. They include
electrochromic and thermochromic coatings, motorized shading
(internal and external) that may be automatically controlled, and fixed
shading devices, particularly for daylighting applications in the
workplace. Newer technologies, such as transparent photovoltaics, can
also generate electricity while transmitting daylight. Such technologies
introduce a new level of complexity in building design since they
generate electricity, have direct and indirect impacts on cooling loads,
as well as electricity consumption for lighting (reducing the need for
electric lighting through daylight). During the cooling season the need
to provide daylight, while preventing excessive solar gains that raise
cooling loads, should be carefully considered.
5. Building-integrated photovoltaics . Photovoltaic panels can serve as
exterior cladding or roof shingles while producing electricity with no
moving parts. Thus, they can be considered a passive element. In some
cases, active heat recovery from BIPV through closed loop (e.g., water
pipes as in solar collector absorber plates) or open loop (flowing air in a